alright guys i swaped a 99ls1, auto into my 86 trans am(305tpi auto, digital dash) i got the car running a few days ago and runs pretty good has a small stumble off idle but i was runnning a open maf and no iat sensor, anways my speed0 was wired (ls1) green/white wire pcm50) to light green/black (TA dash) which on my TA diagram is the 4000ppm speed input wire, ive tried everything i hooked the buffer box all back in and still no speedo- am i missing a ground maybe? the speedo stays at 0mph all the time and is lit up being digital, also the oil pressure guage the only tan wires i have out of my ta dash is tan/black stripe or tan/white stripe, the tan/white is feeding my fuel pump prime. i had the (ls1 tan) hooked to Tan/black TA wire and had no oil pressure guage. any help is apperciated, could it be the pcm?

 

Tan wire under the hood going into the C100 bulkhead connector will be the oil pressure gauge. PCM output from the LS1 PCM (green/white) should be hooked to the 4000ppm output wire (tan or green/white) which goes to the speedo.

 

got it all working, i was looking under the dash for the tan wire, until i pulled the old tpi harness out and looked at it then relized it was under the hood, thanks